After experimenting with the latest jquery-ujs and making an embarrassing mistake, it turns out that the issue is resolved in the latest version.

(Mistake: You may notice I removed a previous post about this topic, where I mistakenly concluded the latest jquery-ujs is not working with JQuery Validation. Thanks to JangoSteve for pointing it out. The post was misleading, so I believe it's best to remove it to avoid confusion. :-)